Abstract: A machining system having a workpiece storage for storing plural workpieces to be machined each of which are machined in plural machining stages. A computer of the system memorizes first information indicating the membership of plural machine tools in plural machine groups suitable for plural different machinings, and second information indicating plural machining stages for machining each of the workpieces and machine groups which can carry out the machinings in respective machining stages. When one of the machine tools becomes empty, the computer finds out what kind of machining is required in the next machining stage of each workpiece so as to find a workpiece which can be machined by a machine group to which the empty machine tool belongs, and the found workpiece is then transferred to the empty machine tool.